Amplifying gauge



Patented Mar. 27, 1951 UNITED STATES eATENT OFFICE j;

2,546,513 AMPLIFYING GAUGE Hans J. Lovenston, Detroit, Mich. Application Mayv 27, 1944, Serial No. 537,699

14 Claims. l

My invention relates to the class of devices which are employed more specifically for verifying the correctness of the intervals between surfaces or points, and an object of my invention, among others, is the production of a gage of the type just mentioned of simple construction and of extreme durability that may be employed for establishing the accuracy of the intervals in a certain and definite manner and to an amplified degree.

One form of a gage embodying my invention and in the construction and use of which the objects herein set out, as well as others, may be attained is illustrated in the accompanying drawings, in which- Figure l is a view in vertical section through a gage embodying my invention.

Figure 2 is a similar view but illustrating some of the interior parts in full.

l Figure 3 is a top plan view of the gage.

Figure 4 is a view partially in vertical section illustrating my improved gage used in connection with a secondary amplifying device.

. Figure 5 is a view similar to Fig. 2 but trating a modification.

Figure 6 is a top plan view of the shown in Fig. 5. My invention relates to an amplifying, mechanism in which amplification is accurate and theoretically constant to its predetermined amplication ratio through its entire movement, and while this may be applied to many tools, instruments, mechanisms, etc. where amplification is required, for the purpose of specifically illus.- trating and describing the invention mention is made of a gage used in the manufacture of interchangeable parts and known in the art ask limit flush pin gages. v

These gages are well known in the art of pro-A duction and are used for verifying or checking the distance of one surface in relationto another. j These flush pin gages consist of a body which contains a sliding member known as a ush pin and which extends from the bottom surface of the body a distance equal to that to be checked from one surface to another. A step is formed on the top surface of the body of a distance equal to the allowable variation permissible in the relation of two surfaces on the work piece relative to each other. The top surface of the flush pin is flush, that is, in the same plane with the top surface of the step on the body when the distance between the two surfaces on the Work piece is at a minimum, and the top surface of the flush pin illus-l device as is flush or in the same plane with the lower step] surface when the distance between the two surfaces to be checked is at a maximum. ,v

In the use of these gages the top surface of the flush pin in relation to the high and low stepl surfaces is located by touch, that is, by movinga-V finger or finger nail over these surfaces. This procedure is sensitive and will easily detect the', position ofthe top surface of the flush pin in relation tothe high and low step surfaces. As longas the top surface of the flush pin is in the same plane with either step surfaces, or in be:

rtween these surfaces, the distance between thev surfaces on the work to be checked is correct and within the specified limits of tolerance.

Obviously the eiiiciencyand usefulness of this type of limit ush pin gage is limited to checking intervalsl where the tolerance is sufficient to per--v mit a step on the body which can be detected by touch. The minimum limit which can be checked efficiently with this type of gage is generally conceded to be about plus or minus .001, this making the step on the body equal to .002. Any meas-v.` urements inside of these limits and Aless than plus or minus' .001 are for practical-purpose amplified by theadditional use of other instruments such as dial-indicators. This combination, known as indicator flush pin gage, is common in the art and well known to those skilled in the use of gages of this type and for which reason a detailed description of its manner of use will not be required.

'Ifo extend the usefulness of the step type ush pin gageand reduce the necessity for the addition of other amplifying instruments as de scribed hereinbefore, I have conceived an amplifying means which .will extend the scope or range of the step type flush pin gage and yet maintain the general principle of the method for deter-j mining dimensionaltolerances. p l vThe same 'amplifying means, but in a slightly modified form in combination with the instruf` ment used on the indicator type flush pin gage will amplify the indicator means on the instru' ment, thereby making this instrument responsive toa greater degree to minute dimensional variations.

The amplifying means is fully enclosed in the body of the gage and well protected frominjury and foreign matter, the ratio of amplification is i constant throughout its entire movement and an:

adjusting means is provided to maintain accurate setting of the gage at any point within its range. The constructionof the amplifying means is sim-v ple and sturdy with substantial and durable con- 3 tact areas on the functional surfaces of its component parts to withstand hard usage and can be produced with precision economically.

ISuch embodiment of the general principle of the amplifying means and the maintenance of the methods of checking dimensional tolerances with the well known types of ushpin gages as described hereinbefore is illustrated in the accompanying drawings in which the numeral 8 denotes the body or stock of my improved gage which is mounted upon and rigidly secured to a base 9, the latter having a guard I extending from the bottom as a protection for the primary plug which is longitudinally slidable in an opening I2 extending in the direction of .depth through the body or stock 8. The lower end of the primary plug may be constituted in the form of an exchangeable plug extension I3.

A guide pin i4 locked in body 8 and protruding partially into opening i2 extends across a fiat surface 50 in a recess on the periphery fof the pri-mary plug to serve as a guide to prevent radial dislocation of the primary plug 'I I. A limiting screw I extending through the body 8 and having a conical point on one end for engagement in a conical recess 3| in the primary plug serves as a means to limit the endwise movement of the primary plug An additional screw 4| is employed to lock adjusting screw |5 when in the desired position.

An opening I6 closed by a plate extends into the body from one sidethereof into the opening |52 and an amplifying plug I8 is inserted for sliding movement in said opening I6. The inner end of this amplifying plug is of tapered shape comprising two angular surfaces |9--2ll diverging from the axial center of the plug |8. As shown in Fig. 1, an adjusting plug 2| is located for adjusting means in a hole extending lengthwise Within the plug I8, the end of said adjusting plug having an angular lcontact surface 48. An adjusting screw 22 split at its threaded end, having its branches pressed a slight distance apart for frictional purpose, is engaged with a threaded hole extending from the outer end o-f the adjusting plug inwardly, the 'outer' end of said screw being accessible when the plate I1 is removed for the reception of a tool for adjusting purposes. One end of a plunger 23 is seated upon a spring 46 in a blind holeextending inwardly from the end of the amplifying plug I8 the opposite end of the plunger being seated against the inner surface of plate V|'| thereby holding the spring 46 under compression to create a force to move the amplifying plug |8 inwardly.

The angular surface on the inner end of the amplifying plug I8 is engaged with 'a similarly formed angular mating surface 24 in the side of the primary plug l and the angular end surface 48 of the adjusting lplug 2| engages with the angular end surface l42 on the secondary plug 25 located in the primary plug and extending to the end thereof as shown in Figs. 1 and .2. Contact between these mati-ng contact surfaces is maintained by the inward force of the. spring 4S acting upon the amplifying plug I8.

The secondary plug 25 is forced inwardly into contact with the angularly shaped end 48 of the adjusting plug 2| by means of a rspring 26 seated in the bottom of a hole extending inwardly from the end of said plug, the opposite end of the spring being seated against a pin extending through a slot in the side of the plug and with its Vopposite ends extended 'into holes in the wall 4 of the hole in the primary plug in which said plug 25 is located.

A step is provided on the outer end of the primary plug Ii as shown in Figs. 1, 2 and 3, the top surface 43 being the higher level of the step and the lower surface 33 being the lower level of the step. The distance between the high step surface 43 and the low step surface 38 is equal to the amplified dimensional tolerance to be obtained.

A plate 28 as shown in Figs. 1 and 2 is secured to the top surface of the body or stock 8. The raised portion of this plate contains a high step surface 2l and a low step surface 23. The distance between the high step surface 2l and low step Vsurface 29 is equal to the actual or true tolerance to be obtained.

It will be noted that while my improved gage described and shown herein embodies the features of the old type flushpin gage so far as the mode rof checking is concerned the measurements are obtained in amplified form and actual or true form, the operation being as follows:

The gage being placed upon a surface as de'- noted by the dotted line a on which measurement is to be obtained within a specified toler-` ance in relation to the surface denoted by the dotted line b, the lower tip end 49 of the extension plug i3 upon contacting the surface denoted by the dotted line b will be raised if the measurements to be obtained are within the proper bounds. The beveled surface 24 on the primary plug Il contacting with the beveled surface 2.3 will push the amplifyingy plug I'B backwardly, and the secondary plug 25 whose beveled end surfacey 42 is contacting and pressing against the beveled end surface 48 on the adjusting plug 2| will move 4proportionately downward. If the upward movement of the primary plug and .the :proporpionate downward movement of the secondary plug 25 is of such dimension that the lower step surface 38 on the upper end lof the primary plug and the end surface 4A `on 'the secondary plug 25 are iush or in the same plane as shown in Fig. 1 the distance between the surface a and b is within the minimum limit of tolerance permitted. Fig. 2 shows the end surfacev 44 of the secondary plug 25 flush or in the. same Vplane with the high step surface 43 on the .end vof the primary plug l! which indicates that the distance from surface a to Inl is within the maximum permissible limit of tolerance. In this instance the primary plug did not move upwardly -tothe same extent as before. The action of the primary plug the amplifying plug |'8 and the secondary plug 25 was the same in this case as described before but the outward movement of the amplifying plug I8 and the downward movement of the secondary plug 25 was less and proportionate to the movement of the primary plug ,|"I.

As described before the distance 'between the low step surface 33 and the high step surface A43 on the pri-mary plug is equal to the permissible tolerance on the distance to be checked in ampli-'- ed form and as long as the end surface 44 `of the secondary plug 25 is flush or in between these two step surf-aces, the ydistance from the surface a to b is within the specified limit of tolerance.

Referring again to Fig. 1, the lower step 'surface 38 on the primary plug and the end surface l44 of the secondary plug 25 are ush or in the same plane, the higher step surface 43V Aon the primary plug is also Yfiush or in the saine plane with the high step surface 2l on the. top plate 28. In this position the distance from the surfacedenoted by the dotted line a to the surface denoted by the dotted line b is within the minimum permissible limit of tolerance to be checked. As shown in Fig. 2 the high step surface 43 on the primary plug I I is flush or in the same plane with the end surface 44 on the secondary plug 25, the high step surface 43 on the primary plug I I is also flush or in the same plane with the lower step surface 23 in the top plate 28. In this position the distance from the surface denoted by the dotted line a to the surface denoted by the dotted line b is within the maximum permissible limit of the tolerance to be checked. The distance between the high step surface 2l and the low step surface 29 on -the top plate 28 isequal to the actual or true permissible tolerance and as long as the high step surface 43 on the primary plug II is flush with either step surface or registers in between these two surfaces the dimension to be checked is within the tolerance specified.

' I want to state again that this gage can be used to check the permissible tolerance in amplified form or in combination to check both the amplified and the actual or true form of the specified tolerance.

' By changing the position of the conical point on the limiting screw I in the body B in relation to the conical recess 3| in the primary plug II, that is, by moving the limiting screw I5 either in or out, the movement of the primary plug II can be adjusted to a minimum of travel necessary and thereby increase the life of accuracy on all sliding surfaces subject to wear.

-As hereinbefore related the angular contact surface 43 on the adjustment plug 2l contacts the angular contact surface 42 on the inner end of the secondary plug 25 and the adjusting screw 22 in the adjustment plug 2l is for the purpose of adjusting the gage to its original correct setting when the contact surface 49 on the primary plug extension I3 is worn or to provide a means to set the gage within the range of the gage capacity without changing the position of or exchanging the plug extension I3. To repeat, when the end surface 49 of the plug extension I3 extends from the lower surface 45 of the base 9 equal to the maximum dimension to be gaged the top surface 44 'of the secondary plunger 25 will be in the same plane with the top step surface 43 on the end of the primary plunger II. When the end surface 49 of the plunger extension I3 extends a distance equal to the minimum dimension to be gaged the top surface 44 of the secondary plunger 25 will be in the same plane as the lower step surface'30 on the end of the primary plunger II It is evident that in order to set the gage it will only be necessary to extend the plunger extension I3 from the rest surface 45 of the base 9 either a distance equal to the minimum or maximum distance to be gaged and then adjust the secondary plug 25 by means of the adjusting plug 2| until the top surface 44 of the secondary plug 25 is in the same plane with either the lower or higher step surface, respectively,von the upper end of the plunger II.

Obviously the spring 46 upon which the plunger 23 is seated is stronger then the actuating spring 25 which holds the secondary plug 25 in contact with the adjustment plug 2l so that the action of the latter to force the plug 25 outwardly will not be prevented.

By changing the angular relationship of the contact surface 24 in the recess of the primary plug II and the corresponding contact surface 2li on the amplifying plug I8 many variations of-V relative degree of movement can be obtained on' the amplifying plug I8 which is in turn trans-- mitted by the adjusting plug 2I to the secondary plug 25. A further Variation of movement of the secondary plug 25 is obtained by changing the angular relationship of the contact surface 42 on the secondary plug 25 and the corresponding contact surface 48 on the adjusting plug 2|, the degree of such relative movements being readily obtained by simple mathematical calculations. The angular positions of the contact surfaces just mentioned, and with reference to Figs. 1 and 2, are limited to a dimensional degree where the upwaid movement of the primary plug II will not cause -the automatic outward movement of the amplifying plug i3, or the spring force of the spring 45 acting upon the amplifying plug I8 will not cause the adjusting plug 2I in contact with the angular surface 42 cn the secondary plug 25 to move the latter plug automatically outward.

The drawing in Fig. 5 shows the angular relationship of the angular contact surface 24 in the recess of the primary plug II with the contact surface 20 on the amplifying plug I8 in conformity with the explanation just mentioned, more specifically, the angular position of the angular contact surface 24 in the recess of the primary plug II is of such dimensional degree that the upward force caused by the upward movement of the primary plug I I and acting through the angular contact surface 24"i1'po'ri the contact surface 20 on the amplifyingplug I8 and normal to these surfaces, is substantially too far in the direction parallel to the longitudinal axis of the primary plug II and therefore will not move the amplifying plug I8 automatically outward. j In this disposition of the angles the degree of movement of the secondary plug 25 relatively to the movement of the primary plug I I will be materially increased. In order to move the amplifying plug I8 outwardly as 'shown in Fig. 5 the amplifying plug I3 is provided with a rack 32- which engages with a pinion 33 rotatably mounted in the body or stock 8, and a screw plug 35 is employed'to hold pinion 33 in position. A spring loaded plunger 34 extending into th e body or stock 8 has a rack 5I which is also engaged with the pinion 33 whereby pressing the spring loaded plunger 34 downwardly the pinion 33 is rotated and affects a backward movement of the amplifying plug IB as shown in Figs. 5 and 6. With the amplifying plug I8 thus disengaged the primary plug II is free to move and find its gaging position on the work piece and upon the release of the downward pressure on the plunger 34 the spring 41 will force the plunger 34 upward and thereby moving the amplifying plug I8 inwardly until the angular surface .20 is in contact with the angular contact surface 24 in the recess of the `primary plug II. Except for the above described modification of operation with reference to Figs. 1 and 2 the function of the amplifying means and the mode of checking is the same, but the amplifying ratio has been increased. 4

In Fig. 4 of the drawings I have illustrated the manner in which further amplification of the movements of the primary plug II may be obtained by the addition of a dial indicator gage 36 which is common in the art and well known to those skilled in the use of gages of this type and for which reason a detailed description of its manner of use will not be required. In making provision for this gage the end of `the primary plug II is socketed and provided with .a slot 31 anda screw 38 for closing the slot and thereby binding the stem .39 of the indicator to secure the latter in place. The plunger 4G of the indicator 35 is vthus positioned against the end of the secondary plunger and any combined movement of the secondary plunger 25 in either direction and .the vmovement of the primary plug I l in the opposite direction will again be amplified with the dial indicator 36, the body of the indicator being' held yon the stem 39 by the primary plug Il` following the movement of this plug in one direction and the indicator plunger d being in contact with the secondary plug 25 following the movement of this plug in the opposite di'- rection. This combination of amplification ratios, one amplification ratio embodied in my new gage and the other embodied in the dial indicator will make the indicator 35 responsive to a greater degree to very small vmovements of the primary plug Il and will cause a substantial movement of the indicator pointer. The position of the indicator pointer in relation to the graduation on the indicator dial is readily located by visual inspection. The addition of an amplifying instrument makes this gage very effective and useful when the amplified step as shown in Figs. 1, 2- and 6 is too small to be checked by touch.

It will be noted that the amplifying plug i8 does not contain the adjustment plug 21 as shown in Figs. 1, 2 and 3 .and described hereinbefore. The angular surface i9 on the amplifying plug I- -contacts .the angular surface 42| of the secondary plug 25 directly and the function of the adjustment plug 2| is substituted by the dial on the indicator 36 which can vbe rotatably moved to .bring the grad-uation -l-ine on the indicator dial denoted by Zero to coincide with the position of theindicator pointer, when the end surface 59 on the primary plug Il extends from the lower surface of the base 9 equal to the basic distance to be gaged.

`The foregoing description is directed solely towards the construction illustrated, but I desire it to be understood that I reserve .the privilege of resorting to all mechanical changes to which the device is susceptible, the invention being defined and limited only by the terms` of the append-ing claims.

I claim: v

1.. A gage for determining dimensional values comprising a body having a base surface, a primary plunger carried by said body and movable in a rectilinear path, one end of said plunger being ladapted to contact a work surface spaced from said base surface, a secondary plunger carried by said body and movable in a 4rectilinear path parallel to the path of movement of said primary plunger, surfaces on each of said plungers inclined to the path of movement of said plungers, a corresponding end of each of said plungers `terminating adjacent a surface 'of said body, indicating surfaces on said plungers` adjacent said end, an indicating surface on said body adjacent the indicating surfaces on said primary and secondary plungers, and a third plunger carried by said `body and movable in a rectilinear path transversely .of the path .of movement .of said other plungers, said third plunger having a pair of inclined surfaces cooperating With and complementary to the respective inclined surfaces of primary and Vsecondary plungers, means urging an inclined `surface of said third plunger into engagement with the complementary inclined surface of said primary plunger, means urging the .inclined 'surface of lthe .secondary plunger into engagement Witt-1` Vthe complementary invtive to movement of' said primary plungerv but opposite direction whereby the dimensional move.- ment of said primary plunger with respect to the base surface of said body is indicated in actual degree by the relative displacement of the indi-i eating surfaces on said primary plunger and said" body and indicated to amplified dimensional degrees by the relative displacement of the ind-i cating surface on said secondary plunger with' respect to the indicating surfaces on said primary plunger and said body.

2. A gage for indicating dimensional values comprising a body having a base surface, a lpri-l mary member carried by said body and movable in a rectilinear path, means operatively associated with said member for contacting a work surface spaced from said base surface, a second-v ary member carried by said body and movable in a rectilinear path, a third member carried by said body and movable in a rectilinear path trans.- versely of the paths of movement of said primary and secondary members, a surface on said primary member, a surface on said third member contacting the surface on said primary member, one of said surfaces being inclined to the path of.v movement of said primary member, a surface on said secondary member, a second surface on said third member contacting the surface on said sec.- ondary member, one of said last two mentioned surfaces being inclined to the path of movement of said secondary member whereby movement of said primary member along its path of travel requires movement o1"- said third member along its path of travel to maintain contact between said primary and thirdmembers and said movement of said third member requires movement of said secondary member along its path of travel to maintain ysaid secondary and third members in contact, said primary and secondary members being positioned .such that their paths of movement are generally parallel whereby when said r work surface engaging means on said primary member are brought into contact with a work surface the relative movement of .said primary and secondary members while in-contact with said third member indicates the position of the work surface relative to said base surface.

3. The combination set forth in claim 2 wherein said primary and secondary members are po` sitioned such that their paths of travel are parallel, said inclined .surfaces being oppositely inclined such that when said primary member is moved in one direction and contact is maintained' between said primary Vand third member and between said third member and said secondary member, said secondary member moves .in a direction .opposite to the direction of movement of said primary member.

4. The combination set forth in claim 2 wherein said inclined surfaces are oppositely inclined and said primary and secondary members are adjacently positioned.

v5. The combination set forth in claim 4 wherein said oppositely inclined surfaces form an acute included angle, said primary and secondary `members lbei-ng positioned sue-h that their paths of movement are parallel whereby said primary and secondary members move in opposite direct-ions to maintain contact With said third members when said third member is ymoved along its path of travel.

6. The combination set forth in claim 2 including means on said primary and secondary members for indicating the positions thereof relative to each other.

7. The combination set forth in claim 2 wherein said primary, secondary, and third members comprise plungers slidable axially on said body.

8. The combination set forth in claim 7 wherein said primary plunger is provided with a bore, said secondary plunger being slidable within the bore of said primary plunger.

9. The combination set forth in claim 7 wherein said primary and secondary plungers have adjacently disposed end surfaces, said inclined surfaces being oppositely inclined such that said primary and secondary plungers move in opposite directions to maintain contact with said third plunger when said third plunger is moved along its path of travel whereby the relative movement of said primary and secondary plungers is indicated by the displacement of said end surfaces.

10. A gage for indicating dimensional values comprising a body having a base surface, a prmary plunger carried by said body and movable in a rectilinear path, one end of said plunger projecting outwardly beyond said base surface for contacting a work surface spaced from said base surface, a secondary plunger carried by said body and movable in a rectilinear path parallel to the path of movement of said primary plunger, a surface on each of said plungers inclined to the path of movement of said plungers, a third plunger carried by said body and movable in a rectilinear path transversely of the paths of movement of said primary and secondary plungers, said third plunger having a pair of oppositely inclined surfaces adapted to slidably contact respectively the inclined surfaces on said primary and secondary plungers whereby movement of said primary plunger along its path of travel requires movement of said third plunger along its path of travel to maintain contact between the inclined surfaces of said primary and third plungers, said movement of said third plunger requiring movement of said secondary plunger along its path of travel and in a direction oppo site to the movement of said primary plunger to maintain contact between the inclined surfaces of said secondary and third plungers, said primary and secondary plungers having means thereon for indicating the relative positions of said primary and secondary plungers.

11. The combination set forth in claim 10 wherein said last mentioned means comprise adjacently disposed end surfaces on said primary and secondary plungers whereby the actual movement of said primary plunger is indicated to an amplied dimensional degree by the displacement of said end surfaces.

12. The combination set forth in claim 2 including means for adjusting one of said inclined surfaces in a direction axially of the member having said inclined surface.

13. The combination set forth in claim 2 wherein said inclined surfaces are carried by said third member and including means for adjusting one of said inclined surfaces in a direction axially of said third member whereby the relative positions of said primary and secondary members may be adjusted for a fixed position of said third member.

14. The combination set forth in claim 10 including means for adjusting one of the oppositely inclined surfaces on said third member in a direction axially of said third member.

HANS J. LOVENSTON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTSy Number Name Date 1,314,888 Mitchell Sept. 2, 1919 1,655,133 Clase July 3, 1928 2,324,998 Dague July 20, 1943 2,339,699 Husband Jan. 18, 1944 2,363,165 viernng 1- Nov. 21, 1944 

